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161.
An abnormal terminal X-Y interchange accounts for most but not all cases of human XX maleness 总被引:14,自引:0,他引:14
To determine if human XX maleness results from an abnormal chromosomal X-Y interchange, we studied the inheritance of the paternal pseudoautosomal region in nine patients. Those six patients in whom Y-specific DNA was found (Y(+)) inherited the entire pseudoautosomal region from the paternal Y chromosome and lost that of the paternal X chromosome. Moreover, in three Y(+) cases, we observed the deletion of a paternal Xp locus tightly linked to the pseudoautosomal region. These results definitively show that an abnormal and terminal X-Y interchange during paternal meiosis causes Y(+)XX maleness. In contrast, no abnormal X-Y interchange was observed in any of the three Y(-) cases analyzed, suggesting that maleness can occur in the absence of any Y-specific DNA. 相似文献
162.
DNA typing of HLA-DR
β
chain genes can discriminate between undetected alleles and real homozygotes 总被引:1,自引:0,他引:1
The polymorphism of HLA-DR antigens has been studied by Southern blot hybridization under conditions specific for the detection of the DR
chain genes. Haplotype-specific patterns were defined with DNA from DR1, 2, 3, 4, 7, w8, w11, w12, and W13 homozygous typing cells, with restriction enzymes Eco RI, Bgl I, and Pvu II. Certain serological specificities, such as DR2, DR3, and DR7, can be encoded by distinct allelic forms of DR
chain genes. The procedure of DNA typing was applied to family analysis of individuals expressing only a single DR specificity upon serological typing. Three cases are described here: (1) in family GR, phenotypic DR 7 homozygotes correspond to genomic heterozygotes, and a novel DR7 allele is described: (2) in family RU, the genes corresponding to a serologically undetected (blank) DR allele were identified by restriction fragment length polymorphism (RFLP); this novel DR haplotype has an RFLP pattern similar to those of the DRw52 family, even though this specificity was not expressed on the DR-blank lymphocytes; (3) in family RG, there is no blank allele, but a homozygote RFLP situation at the DR subregion. 相似文献
163.
Alcaligenes denitrificans NTB-1, previously isolated on 4-chlorobenzoate, also utilized 4-bromo-, 4-iodo-, and 2,4-dichlorobenzoate but not 4-fluorobenzoate as a sole carbon and energy source. During growth, stoichiometric amounts of halide were released. Experiments with whole cells and cell extracts revealed that 4-bromo- and 4-iodobenzoate were metabolized like 4-chlorobenzoate, involving an initial hydrolytic dehalogenation yielding 4-hydroxybenzoate, which in turn was hydroxylated to 3,4-dihydroxybenzoate. The initial step in the metabolism of 2,4-dichlorobenzoate was catalyzed by a novel type of reaction for aerobic organisms, involving inducible reductive dechlorination to 4-chlorobenzoate. Under conditions of low and controlled oxygen concentrations, A. denitrificans NTB-1 converted all 4-halobenzoates and 2,4-dichlorobenzoate almost quantitatively to 4-hydroxybenzoate. 相似文献
164.
165.
An enzyme-linked immunosorbent assay (ELISA) of the "sandwich-type" for sex hormone binding globulin (SHBG) has been developed. A rabbit anti-SHBG antibody (RAb) is immobilized to the microtitre plate. After incubation with standards and samples a second monospecific rabbit anti-SHBG antibody, labelled with alkaline phosphatase is added (RAb). Following further washing substrate is added, colour developed and the plate read at 405 nm wavelength on a standard ELISA plate reader. The assay is not influenced by the presence of steroids at the binding site, and shows good agreement to SHBG binding capacity assay and commercially available IRMA. Its sensitivity, specificity and precision allows its use in the routine laboratory. The SHBG ELISA has been used to measure SHBG concentrations in sera of normal men, women, pregnant women, and women receiving high-dose medroxyprogesterone acetate as a treatment of metastatic breast cancer. 相似文献
166.
The use of bromodeoxyuridine labeling in the human lymphocyte HGPRT somatic mutation assay 总被引:4,自引:0,他引:4
P Ostrosky-Wegman M R Montero C C de Nava R R Tice R Albertini 《Mutation research》1987,191(3-4):211-214
The autoradiographic assay developed by Strauss and Albertini (1979) to quantitate human in vivo somatic mutation at the hypoxanthine guanine phosphoribosyl-transferase locus uses tritiated thymidine to identify mutant cells by their ability to pass through 'S' phase in the presence of 6-thioguanine. An alternative method, based on the incorporation of bromodeoxyuridine (BrdUrd) into the DNA of proliferative cells, followed by differential staining with the fluorescence-plus-Giemsa method, was used to identify 3 classes of lymphocyte nuclei: (a) small darkly stained nuclei, (b) large, reddish-colored nuclei with an apparent nucleolus, and (c) large, bluish-colored nuclei. By double labeling with BrdUrd and tritiated thymidine, it was determined that only the nuclei of the third class had incorporated BrdUrd. These results demonstrate that the technique used for sister-chromatid differentiation can be used to detect putative HGPRT mutants and to determine variant frequencies at the HGPRT locus. 相似文献
167.
Frank M. Maas Luit J. de Kok Ingrid Hoffmann Pieter J. C. Kuiper 《Physiologia plantarum》1987,70(4):713-721
Exposure of spinach (Spinacia oleracea L. cv. Monosa) to 0.25 μl l?1 H2S reduced the relative growth rate by 26, 47 and 60% at 15, 18 and 25°C, respectively. Shoot to root ratio decreased in plants fumigated at 18 and 25°C. Growth of spinach was not affected by a 2-week exposure to 0.10 or 0.25 μl l?1 SO2. Both H2S and SO2 fumigation increased the content of sulfhydryl compounds and sulfate. A 2-week exposure to 0.25 μl l?1 H2S resulted in an increase in sulfhydryl and sulfate content of 250 to 450% and 63 to 248% in the shoots, respectively, depending on growth temperature. Exposure to 0.15 and 0.30 μl l?1 H2S at 20°C for 2 weeks resulted in a 46% increase in sulfate content of the shoots at 0.30 μl l?1 and no detectable increase at 0.15 μl l?1 H2S; the sulfate content of the roots increased by 195 and 145% at 0.15 and 0.30 μl l?1 H2S, respectively. Fumigation with 0.25 μl l?1 SO2 at 20°C for 2 weeks resulted in an increase in sulfhydryl content and sulfate content in the shoots of 285% and 300 to 1100%. H2S fumigation during the 12 h light period or only during the dark period resulted in identical growth reduction and accumulation of sulfhydryl compounds; they were about 50 and 67% of those observed in continuously exposed plants. H2S- and SO2-exposed plants showed an increased transpiration rate, which was mainly caused by an increased dark-period transpiration. No effect of H2S and SO2 on the water uptake of the plants and the osmotic potential of the leaves was detected. Plants fumigated with 0.25 μl l?1 H2S for 2 weeks were smaller and differed morphologically from the control plants by slightly more abaxially curved leaf margins. Cross sections of the leaves showed smaller cells at the margins and smaller and fewer air spaces. The increased transpiration in the H2S-exposed plants is discussed in relation to the observed morphological changes. 相似文献
168.
Immature seeds of apricot (Prunus armeniaca L.) were fed the native gibberellin A5 (GA5) as 1- and 1,2-[3H]GA5 (5.3 Curies per millimole to 16 milliCuries per millimole) at doses (42 nanograms to 10.6 micrograms per seed) 2 to 530 times the expected endogenous level. After 4 days of incubation, seeds were extracted and free [3H]GA-like metabolites were separated from the highly H2O-soluble [3H]metabolites. For high specific activity feeds the retention times (Rts) of radioactive peaks were compared with Rts of authentic GAs on sequential gradient-eluted → isocratic eluted reversed-phase C18 high performance liquid chromatography (HPLC) -radiocounting (RC). From high substrate feeds (530 and 230 × expected endogenous levels) HPLC-RC peak groupings were subjected to capillary gas chromatography-selected ion monitoring (GC-SIM), usually six characteristic ions. The major free GA metabolites of [3H] GA5 were identified as GA1, GA3, and GA6 by GC-SIM. The major highly water soluble metabolite of [3H]GA5 at all levels of substrate GA5 had chromatographic characteristics similar to authentic GA1-glucosyl ester. Expressed as a percentage of recovered radioactivity, low substrate [3H]GA5 feeds (2 × expected endogenous level) yielded a broad spectrum of metabolites eluting at the Rts where GA1, GA3, GA5 methyl ester, GA6, GA22, GA29 (17, 14, 1.6, 7, 1.1, 0.5%, respectively) and GA glucosyl conjugates of GA1, GA3, GA5, and GA8 (33, 11, 1, 0.1%, respectively) elute. Metabolites were also present at Rts where GA glucosyl conjugates of GA6 and GA29 would be expected to elute (8 and 0.1%, respectively). Only 5% of the radioactivity remained as GA5. Increasing substrate GA5 levels increased the proportion of metabolites with HPLC Rts similar to GA1, GA6, and especially GA1 glucosyl ester, primarily at the expense of metabolites with HPLC Rts similar to GA3, GA3-glucosyl ester, and a postulated conjugate of GA6. There was evidence that high doses of substrate GA5 induced new metabolites which often, but not always, differed from GA1, GA3, and GA6 in HPLC Rt. These same metabolites, when analyzed by GC-SIM yielded m/e ions the same as the M+ and other characteristic m/e ions of the above GAs, albeit at differing GC Rt and relative intensities. 相似文献
169.
Different Characteristics of the Two Glutamate Synthases in the Green Leaves of Lycopersicon esculentum 总被引:4,自引:2,他引:2 下载免费PDF全文
The two glutamate synthases, NAD(P)H- and ferredoxin-dependent, from the green leaves of tomato plants (Lycopersicon esculentum L. cv Hellfrucht frühstamm) differed in their chemical properties and catalytic behavior. Gel filtration of NAD(P)H enzyme gave an apparent molecular size of 158 kilodalton, whereas the ferredoxin enzyme molecular size was 141 kilodalton. Arrhenius plots of the activities of the two enzymes showed that the NAD(P)H enzyme had two activation energies; 109.6 and 70.5 kilojoule per mole; the transition temperature was 22°C. The ferredoxin enzyme however, had only one activation energy; 56.1 kilojoule per mole. The respective catalytic activity pH optima for the NAD(P)H- dependent and the ferredoxin dependent enzymes were around 7.3 and 7.8. In experiments to evaluate the effects of modulators aspartate enhanced the NAD(P)H-linked activity, with a Ka value of 0.25 millimolar, but strongly inhibited that of the ferredoxin-dependent glutamate synthase with a Ki of 0.1 millimolar. 3-Phosphoserine was another inhibitor of the ferredoxin dependent enzyme with a Ki value of 4.9 millimolar. 3-Phosphoglyceric acid was a potent inhibitor of the ferredoxin-dependent form, but hardly affected the NAD(P)H-dependent enzyme. The results are discussed and interpreted to propose different specific functions that these activities may have within the leaf tissue cell. 相似文献
170.
J Yajeya A Colino J Criado-Gutiérrez A Fernández de Molina 《Revista Espanola de Fisiología》1987,43(2):185-189
The commissural component of the stria terminalis (S. T.) was studied in Equi-Thesin (92.7 mg/kg) anesthetized rats after their exposure in the caudothalamic surface of both hemispheres. Two types of connection between right and left S. T. across the anterior commissure are described: A "direct" connection set up by fibres that run through the S. T. and join the contralateral S. T., and another "indirect" component, formed by cell axons that receive excitatory synaptic contacts from fibres running in the S. T. 相似文献